Make show rule fallible again

library/src/basics/heading.rs

@@ -71,12 +71,12 @@ impl Prepare for HeadingNode {
 }
 
 impl Show for HeadingNode {
-    fn show(&self, _: &mut Vt, this: &Content, _: StyleChain) -> Content {
+    fn show(&self, _: &mut Vt, this: &Content, _: StyleChain) -> SourceResult<Content> {
         let mut realized = self.body.clone();
         if let Some(Value::Str(numbering)) = this.field("numbers") {
             realized = TextNode::packed(numbering) + SpaceNode.pack() + realized;
         }
-        BlockNode(realized).pack()
+        Ok(BlockNode(realized).pack())
     }
 }
 

library/src/math/mod.rs

@@ -30,7 +30,7 @@ impl MathNode {
 }
 
 impl Show for MathNode {
-    fn show(&self, _: &mut Vt, _: &Content, styles: StyleChain) -> Content {
+    fn show(&self, _: &mut Vt, _: &Content, styles: StyleChain) -> SourceResult<Content> {
         let mut map = StyleMap::new();
         map.set_family(FontFamily::new("NewComputerModernMath"), styles);
 
@@ -44,7 +44,7 @@ impl Show for MathNode {
             realized = realized.aligned(Axes::with_x(Some(Align::Center.into())))
         }
 
-        realized
+        Ok(realized)
     }
 }
 

library/src/meta/link.rs

@@ -50,8 +50,8 @@ impl LinkNode {
 }
 
 impl Show for LinkNode {
-    fn show(&self, _: &mut Vt, _: &Content, _: StyleChain) -> Content {
-        self.body.clone()
+    fn show(&self, _: &mut Vt, _: &Content, _: StyleChain) -> SourceResult<Content> {
+        Ok(self.body.clone())
     }
 }
 

library/src/meta/outline.rs

@@ -44,7 +44,12 @@ impl Prepare for OutlineNode {
 }
 
 impl Show for OutlineNode {
-    fn show(&self, vt: &mut Vt, _: &Content, styles: StyleChain) -> Content {
+    fn show(
+        &self,
+        vt: &mut Vt,
+        _: &Content,
+        styles: StyleChain,
+    ) -> SourceResult<Content> {
         let mut seq = vec![];
         if let Some(title) = styles.get(Self::TITLE) {
             let body = title.clone().unwrap_or_else(|| {
@@ -137,6 +142,6 @@ impl Show for OutlineNode {
             ancestors.push(node);
         }
 
-        BlockNode(Content::sequence(seq)).pack()
+        Ok(BlockNode(Content::sequence(seq)).pack())
     }
 }

library/src/meta/reference.rs

@@ -20,7 +20,7 @@ impl RefNode {
 }
 
 impl Show for RefNode {
-    fn show(&self, _: &mut Vt, _: &Content, _: StyleChain) -> Content {
-        TextNode::packed(format_eco!("@{}", self.0))
+    fn show(&self, _: &mut Vt, _: &Content, _: StyleChain) -> SourceResult<Content> {
+        Ok(TextNode::packed(format_eco!("@{}", self.0)))
     }
 }

library/src/text/deco.rs

@@ -47,8 +47,8 @@ impl<const L: DecoLine> DecoNode<L> {
 }
 
 impl<const L: DecoLine> Show for DecoNode<L> {
-    fn show(&self, _: &mut Vt, _: &Content, styles: StyleChain) -> Content {
-        self.0.clone().styled(
+    fn show(&self, _: &mut Vt, _: &Content, styles: StyleChain) -> SourceResult<Content> {
+        Ok(self.0.clone().styled(
             TextNode::DECO,
             Decoration {
                 line: L,
@@ -57,7 +57,7 @@ impl<const L: DecoLine> Show for DecoNode<L> {
                 extent: styles.get(Self::EXTENT),
                 evade: styles.get(Self::EVADE),
             },
-        )
+        ))
     }
 }
 

library/src/text/misc.rs

@@ -62,8 +62,8 @@ impl StrongNode {
 }
 
 impl Show for StrongNode {
-    fn show(&self, _: &mut Vt, _: &Content, styles: StyleChain) -> Content {
-        self.0.clone().styled(TextNode::DELTA, Delta(styles.get(Self::DELTA)))
+    fn show(&self, _: &mut Vt, _: &Content, styles: StyleChain) -> SourceResult<Content> {
+        Ok(self.0.clone().styled(TextNode::DELTA, Delta(styles.get(Self::DELTA))))
     }
 }
 
@@ -104,8 +104,8 @@ impl EmphNode {
 }
 
 impl Show for EmphNode {
-    fn show(&self, _: &mut Vt, _: &Content, _: StyleChain) -> Content {
-        self.0.clone().styled(TextNode::EMPH, Toggle)
+    fn show(&self, _: &mut Vt, _: &Content, _: StyleChain) -> SourceResult<Content> {
+        Ok(self.0.clone().styled(TextNode::EMPH, Toggle))
     }
 }
 

library/src/text/raw.rs

@@ -56,7 +56,7 @@ impl Prepare for RawNode {
 }
 
 impl Show for RawNode {
-    fn show(&self, _: &mut Vt, _: &Content, styles: StyleChain) -> Content {
+    fn show(&self, _: &mut Vt, _: &Content, styles: StyleChain) -> SourceResult<Content> {
         let lang = styles.get(Self::LANG).as_ref().map(|s| s.to_lowercase());
         let foreground = THEME
             .settings
@@ -109,7 +109,7 @@ impl Show for RawNode {
         map.set(TextNode::SMART_QUOTES, false);
         map.set_family(FontFamily::new("IBM Plex Mono"), styles);
 
-        realized.styled_with_map(map)
+        Ok(realized.styled_with_map(map))
     }
 }
 

library/src/text/shift.rs

@@ -43,7 +43,12 @@ impl<const S: ShiftKind> ShiftNode<S> {
 }
 
 impl<const S: ShiftKind> Show for ShiftNode<S> {
-    fn show(&self, vt: &mut Vt, _: &Content, styles: StyleChain) -> Content {
+    fn show(
+        &self,
+        vt: &mut Vt,
+        _: &Content,
+        styles: StyleChain,
+    ) -> SourceResult<Content> {
         let mut transformed = None;
         if styles.get(Self::TYPOGRAPHIC) {
             if let Some(text) = search_text(&self.0, S) {
@@ -53,12 +58,12 @@ impl<const S: ShiftKind> Show for ShiftNode<S> {
             }
         };
 
-        transformed.unwrap_or_else(|| {
+        Ok(transformed.unwrap_or_else(|| {
             let mut map = StyleMap::new();
             map.set(TextNode::BASELINE, styles.get(Self::BASELINE));
             map.set(TextNode::SIZE, styles.get(Self::SIZE));
             self.0.clone().styled_with_map(map)
-        })
+        }))
     }
 }
 

src/model/realize.rs

@@ -47,7 +47,7 @@ pub fn realize(
     if let Some(showable) = target.with::<dyn Show>() {
         let guard = Guard::Base(target.id());
         if realized.is_none() && !target.is_guarded(guard) {
-            realized = Some(showable.show(vt, target, styles));
+            realized = Some(showable.show(vt, target, styles)?);
         }
     }
 
@@ -139,7 +139,12 @@ pub trait Prepare {
 #[capability]
 pub trait Show {
     /// Execute the base recipe for this node.
-    fn show(&self, vt: &mut Vt, this: &Content, styles: StyleChain) -> Content;
+    fn show(
+        &self,
+        vt: &mut Vt,
+        this: &Content,
+        styles: StyleChain,
+    ) -> SourceResult<Content>;
 }
 
 /// Post-process a node after it was realized.